Purpose: Total mesorectal excision is a standard technique for rectal cancer. The whole-mount section can encompass the entire specimen, so it is a more appropriate for measuring circumferential margin than conventional section. We analyzed the clinical characteristics and prognosis based on lateral margins measured by whole-mount sections.
Materials and methods: Medical records of patients who were operated on for T3 rectal cancer from 2005 to 2015 were reviewed retrospectively. A total of 154 patients were included. The slides of the whole-mount sections were re-reviewed by a single pathologist.
Results: We divided the groups according to the length of the lateral margin (LM: 1mm, 1.5mm and 2mm). There was significantly frequent lymphovascular invasion and N state was higher when LM was short in all groups. There were more micrometastasis in group LM.
Keywords: Lateral margin; Neoplasm micrometastasis; Prognosis; Rectal neoplasms; Whole mount section.